Information processing apparatus, control method of information processing apparatus, and program of information processing apparatus

Abstract

To enable a user to easily specify an accuracy guarantee range that is an index of a tolerance accompanied with AD conversion of an IO unit to dynamically grasp the accuracy guarantee range.SOLUTION: An information processor comprises an accuracy guarantee specification unit 13 that specifies an accuracy guarantee range of an analog signal based on an analog signal that an analog unit handles, and prescribed information, and a storage unit 20 that stores the prescribed information. The information processor can automatically specify the accuracy guarantee range and detect accuracy deterioration of the analog signal.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the accuracy guarantee range of an analog unit.

Background Art

[0002] In devices using a PLC (Programming Logic Controller) such as in warehouses and factories, various sensors are used. Among the sensors, there are sensors with analog outputs such as temperature, and an analog input IO unit (Input / Output Unit; hereinafter also referred to as an analog unit) may be used. In an analog input IO unit, an analog signal such as voltage or current is AD-converted into a digital value by an AD (Analog-Digital) converter.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When performing AD conversion, errors are inevitable. Patent Document 1 discloses a technique for determining the deterioration state of a battery cell from the voltage measurement error of the battery cell. Thus, by grasping the measurement error associated with AD conversion, abnormal situations can be prevented, and it can be useful for investigating the cause of the abnormality.

[0005] Conventionally, to grasp the measurement error of the analog quantity in a device, it was necessary for a person to manually calculate according to the procedure described manually. Even in this case, it can be a clue for investigating the cause when some abnormality occurs. However, it took time for the user to specify the accuracy guarantee range, which is an index of the error associated with the AD conversion of the IO unit, and it was difficult to grasp the accuracy guarantee range dynamically.

[0006] One aspect of the present invention aims to specify the accuracy guarantee range of an analog signal handled by an analog unit.

Means for Solving the Problems

[0007] To solve the above problems, an information processing apparatus according to one aspect of the present invention includes an accuracy guarantee specifying unit that specifies an accuracy guarantee range of an analog signal based on the analog signal handled by an analog unit and predetermined information regarding the analog signal, and a storage unit that stores the predetermined information.

[0008] According to the above configuration, the accuracy guarantee range can be automatically specified, and a decrease in the accuracy of the analog signal can be detected. Therefore, it is possible to prevent troubles associated with a decrease in the accuracy of the analog signal.

[0009] The predetermined information may include a procedure for specifying the accuracy guarantee range, information regarding a device that handles the analog signal, and / or environmental information of the analog unit.

[0010] According to the above configuration, the predetermined information can specify the accuracy guarantee range by processing information of a device such as the type or connection form of a sensor and / or environmental information around the analog unit according to a predetermined procedure such as a flowchart.

[0011] The information processing apparatus may further include an acquisition unit that acquires the environmental information.

[0012] According to the above configuration, the environmental information can be acquired, and the environmental information can be used to specify the accuracy guarantee range.

[0013] The environmental information may include the ambient temperature around the analog unit and / or the installation direction.

[0014] According to the above configuration, as environmental information, ambient temperature and / or installation direction may be included, and the thermal characteristics of electronic components in the analog unit and / or the heat dissipation performance of the analog unit itself based on the installation direction of the analog unit can be considered when specifying the accuracy guarantee range.

[0015] The information processing apparatus may further include an output unit that outputs the accuracy guarantee range.

[0016] According to the above configuration, the accuracy guarantee range can be output and used for processing by upper-level devices or a warning can be issued to the administrator.

[0017] The output unit may display the level of guaranteed accuracy on a display device.

[0018] According to the above configuration, since the approximate value of the accuracy guarantee range can be displayed on the display unit, it is possible to confirm the deterioration of the state of the analog unit itself just by visually observing the analog unit. Therefore, problems can be easily identified and countermeasures can be taken early.

[0019] The analog signal may be an input from a thermocouple or a load cell.

[0020] According to the above configuration, the analog unit can be a temperature input unit or a load cell input unit.

[0021] A control method for an information processing apparatus according to another aspect includes an acquisition step of acquiring predetermined information regarding an analog signal handled by an analog unit from a storage unit, and an accuracy guarantee specification step of specifying an accuracy guarantee range of the analog signal based on the analog signal and the predetermined information.

[0022] An information processing apparatus according to each aspect of the present invention may be implemented by a computer. In this case, an accuracy guarantee program, a storage program, and a computer-readable recording medium recording the same for implementing the information processing apparatus by operating the computer as each part (software element) included in the information processing apparatus also fall within the scope of the present invention.

Effects of the Invention

[0023] According to one aspect of the present invention, it is possible to specify the accuracy guarantee range of an analog signal handled by an analog unit.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

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Figure 4

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Figure 7

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Figure 10

Figure 11

Mode for Carrying Out the Invention

[0025] 〔Embodiment 1〕 Hereinafter, embodiments according to one aspect of the present invention (hereinafter also referred to as "the present embodiment") will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their description will not be repeated.

[0026] §1 Application Example First, an example of a scene to which the present invention is applied will be introduced. The information processing apparatus according to this application example is an analog unit (IO unit (Input / Output Unit)) for analog input / output, and inputs an analog signal from a sensor for analog output. The analog unit includes an accuracy guarantee specifying unit that specifies an accuracy guarantee range, which is an index of the AD conversion accuracy of the input analog signal, and a storage unit that collectively stores a procedure for specifying the accuracy guarantee range. Here, the accuracy guarantee range is a range of values of the input / output accuracy of the analog unit guaranteed by the manufacturer or the state of the input / output accuracy. Specifically, the accuracy guarantee range is an index representing the error of the input / output value associated with the conversion of the electric circuit and the conversion circuit that input / output the analog signal of the device for AD conversion, or the degree of temperature drift of the analog device.

[0027] The accuracy guarantee specifying unit specifies the accuracy guarantee range of the analog signal input / output by the analog unit according to the procedure. By specifying the accuracy guarantee range, the degree of the accuracy guarantee range of the analog unit can be notified to the administrator via the output unit.

[0028] §2 Configuration Example FIG. 1 is a block diagram showing the configuration of the main part of the analog system 100a according to Embodiment 1. The analog system 100a includes a temperature input unit 1a and a thermocouple 111.

[0029] (Configuration of Thermocouple 111) The thermocouple 111 is a sensor that has the function of outputting the temperature at the measurement location as an analog signal. Here, a thermocouple is used to explain the temperature input unit as an example of the analog unit, but any analog device may be used. Examples of analog devices include, but are not limited to, thermocouples, resistance temperature detectors, acceleration sensors, load cells, pressure gauges, and flow meters. The analog output of the analog device may be voltage output, current output, or IEPE output, and the output range is also arbitrary.

[0030] (Configuration of Temperature Input Unit 1a) The temperature input unit 1a includes a control unit 10a, a storage unit 20, and a display 141. The temperature input unit 1a is an analog unit that can connect various types of thermocouples and measures temperature by the thermoelectromotive force in the thermocouple 111.

[0031] The storage unit 20 stores parameters, programs, and processing procedures necessary for specifying the accuracy guarantee range of the analog unit. The storage unit 20 may be composed of a non-volatile memory.

[0032] The display 141 displays the degree of the accuracy guarantee range according to the command of the control unit 10a. Here, the display 141 has displays from Rank0 to Rank3, and one of them lights up as a result of the processing of the control unit 10a. Also, the display 141 may be any display device that performs arbitrary displays.

[0033] (Configuration of Control Unit 10a) The control unit 10a comprehensively controls each part of the temperature input unit 1a. The control unit 10a includes a measured value acquisition unit 11, an environmental information acquisition unit 12a (acquisition unit), an accuracy guarantee specification unit 13, and an output unit 14.

[0034] The measured value acquisition unit 11 performs a process of AD-converting the analog signal input from the thermocouple 111, which is a thermocouple input, and converting it into a digital value. The measured value acquisition unit 11 outputs the converted digital value to the accuracy guarantee specification unit 13.

[0035] The environmental information acquisition unit 12a acquires the environmental information of the analog unit. The environmental information may include the power consumption of the unit adjacent to the analog unit, the ambient temperature around the analog unit, or the installation direction of the analog unit, etc., and some environmental information may be missing. These environmental information are set in advance by the administrator in the storage unit 20, and the environmental information acquisition unit 12a reads the set values. The environmental information acquisition unit 12a outputs the environmental information to the accuracy guarantee specifying unit 13.

[0036] The accuracy guarantee specifying unit 13 specifies the accuracy guarantee range of the analog quantity based on the analog signal handled by the analog unit, various parameters, and the predetermined information including the procedure for specifying the accuracy guarantee range. The various parameters include environmental information such as the ambient temperature or installation direction of the analog unit, and / or information related to the device handling the analog signal such as the sensor type. The specified accuracy guarantee range is output to the output unit 14.

[0037] Based on the input accuracy guarantee range, the output unit 14 displays the level of the accuracy guarantee range on the display 141. The level of the accuracy guarantee range is an index obtained by classifying the specified accuracy guarantee range into several levels. The user can determine whether the accuracy guarantee range is sufficient just by checking the level. Also, the output unit 14 may output the digital value (measurement value) measured by the analog unit and the accuracy guarantee range together to a higher-level device (for example, a PLC).

[0038] §3 Operation Example Taking a certain temperature input unit 1a among the analog units as an example, an example of the procedure for specifying the accuracy guarantee range will be described as an operation example. This procedure for specifying the accuracy guarantee range is just an example and is not limited thereto.

[0039] FIG. 2 is a flowchart showing a procedure for specifying an accuracy guarantee range in the temperature input unit according to Embodiment 1. FIG. 3 is a table showing the types of thermocouples supported by the temperature input unit according to Embodiment 1. FIG. 4 is a flowchart showing a procedure for specifying a cold junction compensation error used for specifying the accuracy guarantee range of the temperature input unit according to Embodiment 1.

[0040] (Specification of the accuracy guarantee range in the temperature input unit) Based on FIG. 2, a procedure for specifying the accuracy guarantee range in the temperature input unit 1a will be described.

[0041] Prior to specifying the accuracy guarantee range, it is necessary to set in advance in the storage unit 20 the change in the ambient temperature of the temperature input unit 1a. The change in the ambient temperature is the increase or decrease in the ambient temperature of the temperature input unit 1a with respect to the reference temperature determined by the device specifications. That is, when the ambient temperature is 30°C and the reference temperature is 25°C, the change in the ambient temperature is 5°C.

[0042] In S11, the accuracy guarantee specifying unit 13 checks whether the energization time of the temperature input unit 1a is equal to or longer than a predetermined time. The energization time is the elapsed time since the power of the analog unit was turned on, and is obtained by counting up in the firmware of the analog unit. The predetermined time is, for example, 30 minutes, and is the time until the temperature characteristics of the analog unit become stable depending on the analog unit itself and the temperature of the environment in which the analog unit is installed. The measurement of the energization time is performed by the temperature input unit 1a. If it is equal to or longer than the predetermined time (Yes in S11), the process proceeds to S12. If it is less than the predetermined time (No in S11), the process proceeds to S17.

[0043] In S12, the accuracy guarantee specifying unit 13 specifies the cold junction compensation error. The procedure for specifying the cold junction compensation error will be described later. A thermocouple is a sensor that measures the temperature difference between a reference junction (cold junction) connected to the temperature input unit and a temperature measurement junction (hot junction) installed at the temperature measurement point by the Seebeck effect in which current flows between dissimilar metals. That is, since a thermocouple measures relative temperature, another sensor capable of measuring the temperature at the reference junction as absolute temperature is required. The cold junction compensation error is an error that occurs when the temperature at the reference junction is separately measured by a sensor such as another thermistor or a resistance temperature detector and added to the relative temperature measured by the thermocouple.

[0044] In S13, the accuracy guarantee specifying unit 13 checks whether the condition for the cold junction compensation error is guaranteed. If the condition for the cold junction compensation error is guaranteed (Yes in S13), the process proceeds to S14. If the condition for the cold junction compensation error is not guaranteed (No in S13), the process proceeds to S17.

[0045] In S14, the accuracy guarantee specifying unit 13 refers to the input mode (input type) corresponding to the conversion time and the type of thermocouple stored in the storage unit 20, and obtains the reference accuracy and the temperature coefficient using the current measured value. The conversion time represents the time required for AD conversion, and the input mode represents the type of the thermocouple 111. FIG. 3 is a table showing the temperature range that can be measured for each type of thermocouple and the reference accuracy and the temperature coefficient for each temperature range at a certain conversion time. The storage unit 20 stores a table in which the conversion time, the type of thermocouple, the range of the measured temperature, the reference accuracy, and the temperature coefficient are associated with each other. For example, when the measured temperature of a K-type thermocouple is 500 ° C., the temperature range is -200 to 1300 ° C., and there are three stages of the measured temperature. In the range of -100 to 400 ° C., the reference accuracy is ± 1.5 ° C. and the temperature coefficient is ± 0.30 ° C. / ° C. Also, the environmental information acquisition unit 12a reads the change in the ambient temperature from the storage unit 20. The conversion time is a fixed value unique to the analog unit and takes a unique value here. However, depending on the analog unit, there are cases where the conversion accuracy decreases instead of performing high-speed conversion by changing the conversion time, and the conversion time is a parameter used for calculating the reference accuracy.

[0046] In S15, the accuracy guarantee specifying unit 13 specifies the accuracy guarantee range according to the following formula.

[0047] Accuracy guarantee range = reference accuracy + temperature characteristic × ambient temperature change + cold junction compensation error In the above formula, since the signs of the reference characteristic, the temperature characteristic, and the cold junction compensation error are the values of plus or minus errors, the calculation is performed using the absolute values.

[0048] In S16, the output unit 14 determines whether the accuracy guarantee range is within the first range. If the accuracy guarantee range falls within the first range (Yes in S16), the process proceeds to S18. If the accuracy guarantee range does not fall within the first range (No in S16), the process proceeds to S17.

[0049] In S17, the output unit 14 determines that the accuracy cannot be guaranteed, and issues a command to turn on the display of Rank0 on the display 141.

[0050] In S18, the output unit 14 determines whether the accuracy guarantee range is within the second range, and outputs the accuracy guarantee range to the output unit 14. The second range is a range inside the first range and is of higher accuracy. If the accuracy guarantee range is within the second range (Yes in S18), the process proceeds to S20. If the accuracy guarantee range is outside the second range (No in S18), the process proceeds to S19.

[0051] In S19, the output unit 14 determines that the accuracy can be guaranteed and the accuracy guarantee range is within the first range, and issues a command to turn on the display of Rank1 on the display 141.

[0052] In S20, the output unit 14 determines whether the accuracy guarantee range is within the third range, and outputs the accuracy guarantee range to the output unit 14. The third range is a range inside the second range and is of higher accuracy. If the accuracy guarantee value is within the third range (Yes in S20), the process proceeds to S22. If the accuracy guarantee range is outside the third range (No in S20), the process proceeds to S21.

[0053] In S21, the output unit 14 determines that it is a condition where accuracy can be guaranteed and the accuracy guarantee range is within the second range, and issues a command to turn on the display of Rank2 on the display 141.

[0054] In S22, the output unit 14 determines that it is a condition where accuracy can be guaranteed and the accuracy guarantee range is within the third range, and issues a command to turn on the display of Rank3 on the display 141.

[0055] (Specification of cold junction compensation error) Based on FIG. 4, the procedure for specifying the cold junction compensation error in S12 in the temperature input unit 1a will be described.

[0056] Prior to specifying the cold junction compensation error, it is necessary to set the input mode, the installation direction of the temperature input unit 1a, and the power consumption of the adjacent unit in advance in the storage unit 20. Also, regarding the power consumption of the adjacent unit, when the setting software writes settings to the analog unit, it may be automatically generated and set from the configuration of the analog system 100a set by the setting software. The adjacent unit is a unit connected to the analog unit and sharing a power supply with the analog unit. Adjacent units may be connected to both sides of the analog unit.

[0057] In S31, the environment information acquisition unit 12a determines whether the installation direction of the temperature input unit 1a is a predetermined installation direction and whether the power consumption of the unit adjacent to the temperature input unit is equal to or less than the first power threshold. For example, the installation direction of the temperature input unit 1a can be front mounting (vertical or horizontal), ceiling mounting, floor mounting, etc. For example, the predetermined installation direction is front mounting (vertical). If the conditions are not met (No in S31), the process proceeds to S32. If the conditions are met (Yes in S31), the process proceeds to S41.

[0058] In S32, the environmental information acquisition unit 12a determines whether the installation direction of the temperature input unit 1a is a predetermined installation direction and the power consumption of the unit adjacent to the temperature input unit is equal to or less than a second power threshold, or whether the installation direction of the temperature input unit 1a is not the predetermined installation direction and the power consumption of the unit adjacent to the temperature input unit is equal to or less than the second power threshold. In short, the environmental information acquisition unit 12a determines whether the condition that the power consumption of the unit adjacent to the temperature input unit is equal to or less than the second power threshold is satisfied. The second power threshold is a value larger than the first power threshold. If the condition is not satisfied (No in S32), the process proceeds to S33. If the condition is satisfied (Yes in S32), the process proceeds to S51.

[0059] In S33, the accuracy guarantee specifying unit 13 determines that there is no guarantee of cold junction compensation error.

[0060] In S41, the accuracy guarantee specifying unit 13 refers to the storage unit 20 and determines whether the first condition is satisfied based on the input mode of the connected thermocouple 111 and the current measured value. Examples of the first condition include the condition that the input mode of the thermocouple is any one of J, E, K, and N, and the temperature measured by the measurement value acquisition unit 11 is equal to or lower than a temperature threshold (for example, -100°C) corresponding to the input mode. Thus, the first condition may be determined based on the input mode, the measured value, etc. The temperature threshold may vary depending on the input mode. If the condition is satisfied (Yes in S41), the process proceeds to S43. If the condition is not satisfied (No in S41), the process proceeds to S42.

[0061] In S42, the accuracy guarantee specifying unit 13 refers to the storage unit 20 and determines whether the second condition is satisfied based on the input mode of the connected thermocouple 111 and the current measured value. Examples of the second condition include the condition that the input mode of the thermocouple is W. If the condition is satisfied (Yes in S42), the process proceeds to S43. If the condition is not satisfied (No in S42), the process proceeds to S44.

[0062] In S43, the accuracy guarantee specifying unit 13 determines that the cold junction compensation error is within the first error range. The first error range is, for example, ±3.0°C.

[0063] Also, in S44, the accuracy guarantee specifying unit 13 determines that the cold junction compensation error is within the second error range. The second error range is, for example, no guarantee of cold junction compensation error (i.e., the second error range is infinite).

[0064] In S51, the accuracy guarantee specifying unit 13 refers to the storage unit 20 and determines whether the first condition is satisfied based on the input mode of the connected thermocouple 111 and the current measured value. If the condition is satisfied (Yes in S51), the process proceeds to S52. If the condition is not satisfied (No in S51), the process proceeds to S53.

[0065] In S52, the accuracy guarantee specifying unit 13 determines that the cold junction compensation error is within the third error range. The third value is, for example, ±7.0°C, which is wider than the first error range.

[0066] In S53, the accuracy guarantee specifying unit 13 refers to the storage unit 20 and determines whether the second condition is satisfied based on the input mode of the connected thermocouple 111 and the current measured value. If the condition is satisfied (Yes in S53), the process proceeds to S54. If the condition is not satisfied (No in S53), the process proceeds to S55.

[0067] In S54, the accuracy guarantee specifying unit 13 determines that the cold junction compensation error is within the fourth error range. The fourth error range is, for example, ±9.0°C, which is wider than the third error range.

[0068] Also, in S55, the accuracy guarantee specifying unit 13 determines that the cold junction compensation error is within the fifth error range. The fifth error range is, for example, no guarantee of cold junction compensation error, etc., and is wider than the fourth error range.

[0069] (Example of specifying the accuracy guarantee range in the temperature input unit) Here, a specific example of the accuracy guarantee range in a certain temperature input unit 1a is shown. As specific conditions, the energization time is 30 minutes or more, the installation direction is front-mounted, the power consumption of the adjacent unit is 1.5 W or less, the input mode is a K thermocouple, the conversion time is 250 msec, the measured temperature is 100 °C, and the ambient temperature is 30 °C.

[0070] First, a conventional method for specifying the accuracy guarantee range is shown for comparison. Conventionally, a person has to check the energization time and the installation direction, use a dedicated tool to check the power consumption, input mode, and measured temperature of the adjacent unit, and install a temperature sensor to measure the ambient temperature and determine the variation. Since it is necessary to specify the accuracy guarantee range according to a predetermined procedure while referring to these manually or to a data sheet, it is very complicated.

[0071] In contrast, in this embodiment, first, at S11, the timer that is being counted up by the firmware since the start of energization of the temperature input unit 1a is checked. Since the energization time is 30 minutes or more and a predetermined time or more, the process proceeds to S12. At S12, when the cold junction compensation error is specified from the conditions of the installation direction, the power consumption of the adjacent unit, the input mode, and the measured temperature, the process proceeds to S44. For example, assume that the cold junction compensation error is ±1.2 °C.

[0072] Due to the cold junction compensation error, the process proceeds to S14. Since the ambient temperature is 30 °C, when the reference temperature is 25 °C, the change in the ambient temperature is 5 °C. From the conditions of the input mode, conversion time, and measured temperature, the reference accuracy is ±1.5 °C, and the temperature coefficient is ±0.30 °C / °C. When the accuracy guarantee range is specified from these conditions, it is as follows.

[0073] Accuracy guarantee range = ±1.5 °C + ±0.30 °C / °C × 5 °C + ±1.2 °C = ±4.2 °C Here, in the calculation of the accuracy guarantee range, due to the numerical values of the errors, it is the sum of the error ranges with plus and minus signs. When adding the error ranges, the absolute values of the errors shall be added. That is, the sum of the positive-side errors is taken as the upper limit of the error range, and the sum of the negative-side errors is taken as the lower limit of the error range.

[0074] Since the accuracy guarantee range is ±4.2°C (< the third threshold value), the process proceeds to S22, and the display of Rank3 lights up by the output unit 14. These processes are automatically performed.

[0075] §4 Operations and Effects By setting several parameters in the storage unit 20 in advance, the accuracy guarantee range can be automatically and real-time specified from the parameters and the measured values according to a predetermined procedure.

[0076] In addition, since an approximate value of the accuracy guarantee range can be confirmed by the display without preparing a dedicated program for confirming and processing the accuracy guarantee range, it is easy to confirm the state of the analog device in regular maintenance.

[0077] 〔Embodiment 2〕 Another embodiment of the present invention will be described below. For the sake of convenience of explanation, members having the same functions as those described in the above embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

[0078] FIG. 5 is a block diagram showing the configuration of the main part of the analog system 100b according to Embodiment 2. In Embodiment 2, different from Embodiment 1, the accuracy guarantee range can be specified without separately setting a part of the parameters necessary for specifying the accuracy guarantee range in the storage unit 20 by a person. Of course, some parameters such as the input mode need to be set separately.

[0079] In the analog system 100b, the temperature input unit 1a has changed to the temperature input unit 1b, the control unit 10a has changed to the control unit 10b, and the environmental information acquisition unit 12a has changed to the environmental information acquisition unit 12b. Also, the temperature input unit 1b includes a temperature sensor 121 and an acceleration sensor 122.

[0080] The temperature sensor 121 is a temperature sensor built-in or externally attached within the analog unit. As the temperature sensor, a sensor for measuring absolute temperature such as a thermistor or a resistance temperature detector is used. Depending on the type of the analog unit, the temperature sensor 121 may not be provided.

[0081] The acceleration sensor 122 is an acceleration sensor built-in within the analog unit. The acceleration sensor may be an inclination sensor, and may be any sensor capable of determining the installation direction of the analog unit.

[0082] Unlike the environmental information acquisition unit 12a, the environmental information acquisition unit 12b automatically acquires the environmental information of the analog unit instead of reading a set value preset by a person in advance. Regarding the ambient temperature of the analog unit, the environmental information acquisition unit 12b acquires it by the temperature sensor 121, and regarding the installation direction of the analog unit, it acquires it by the acceleration sensor 122.

[0083] Therefore, in the second embodiment, in order to automatically acquire the parameters necessary for specifying the accuracy guarantee range preset by a person, it becomes possible to determine the accuracy guarantee range and it can be easily used just by simply installing and starting up the analog unit. Also, there is an advantage that it can automatically respond without changing the settings even when the environmental information changes.

[0084] Furthermore, by notifying the PLC, which is the host device of the analog unit, of the accuracy guarantee range by the output unit 14, any processing based on the accuracy guarantee range can be performed by a program in the PLC. For example, when the accuracy guarantee range becomes larger than a predetermined range and deteriorates, the PLC that has acquired the information of the temperature input unit 1b can automatically stop production and notify the administrator to check the state of the analog system 100b.

[0085] 〔Embodiment 3〕 Another embodiment of the present invention will be described below.

[0086] FIG. 6 is a block diagram showing the configuration of the main part of the analog system 100c according to Embodiment 3. In Embodiment 3, different from Embodiment 1, the specification of the accuracy guarantee range is performed not by the analog unit but by the PLC acting as the master of the analog unit.

[0087] The analog system 100c includes a PLC 2c, a temperature input unit 3c, and a thermocouple 111. The PLC 2c includes a control unit 10c, a storage unit 20, and a display 141. The control unit 10c includes an environmental information acquisition unit 12a, an accuracy guarantee specification unit 13, an output unit 14, and a unit communication unit 15c.

[0088] The unit communication unit 15c communicates with the temperature input unit 3c to acquire the digital value of the analog quantity of the thermocouple 111. Also, at the same time, the unit communication unit 15c acquires the input mode and conversion time from the non-volatile memory of the temperature input unit 3c.

[0089] The temperature input unit 3c includes a measurement value acquisition unit 11. The temperature input unit 3c converts the analog quantity of the thermocouple 111 into a digital value and communicates with the unit communication unit 15c. Also, at the same time, the input mode and conversion time are acquired from the non-volatile memory of the temperature input unit 3c and communicated.

[0090] The PLC 2c acquires the measured temperature, input mode, and conversion time from the temperature input unit 3c, and the environment information acquisition unit 12a acquires the installation direction, power consumption of adjacent units, and ambient temperature from the storage unit 20, and specifies the accuracy guarantee range through the same processing as in the first embodiment.

[0091] Therefore, unlike the first embodiment, there is no change in the analog unit, and the accuracy guarantee range can be specified only by modifying the program of the PLC acting as the master. Thus, it is suitable for modifying the existing system.

[0092] Furthermore, in order to specify the accuracy guarantee range within the PLC, the control unit 10c of the PLC 2c can execute a user - specific program based on the specified accuracy guarantee range. The control unit 10c of the PLC 2c can automatically stop production and notify the administrator to check the state of the analog system 100b, etc.

[0093] 〔Embodiment 4〕 Other embodiments of the present invention will be described below.

[0094] FIG. 7 is a block diagram showing the configuration of the main part of the analog system 100d according to the fourth embodiment. In the fourth embodiment, unlike the first embodiment, the specification of the accuracy guarantee range is not performed by the analog unit, but by the PLC that is the master of the analog unit, and all the parameters required for specifying the accuracy guarantee range are acquired from the analog unit.

[0095] The analog system 100d includes a PLC 2d, a temperature input unit 3d, and a thermocouple 111. The PLC 2d includes a control unit 10d, a storage unit 20, and a display 141. The control unit 10d includes an accuracy guarantee specification unit 13, an output unit 14, and a unit communication unit 15d.

[0096] The unit communication unit 15d is different from the unit communication unit 15c in that, unlike in the first embodiment, it also acquires the parameters that the environment information acquisition unit acquired from the temperature input unit 3d. The acquired parameters are output to the accuracy guarantee specification unit 13.

[0097] Therefore, the temperature input unit 3d includes a measurement value acquisition unit 11, an environmental information acquisition unit 12d, a temperature sensor 121, and an acceleration sensor 122. The temperature input unit 3d causes the measurement value acquisition unit 11 to convert the analog quantity of the thermocouple 111 into a digital value, communicate it to the unit communication unit, and acquire and communicate the input mode and conversion time from the non-volatile memory of the temperature input unit 3d. At the same time, the environmental information acquisition unit 12d communicates the ambient temperature and installation direction acquired from the temperature sensor 121 and the acceleration sensor 122 to the unit communication unit 15d.

[0098] Therefore, the PLC 2d acquires the measured temperature, input mode, conversion time, ambient temperature, and installation direction from the temperature input unit 3d, and specifies the accuracy guarantee range by the same process as in the first embodiment.

[0099] Therefore, unlike the first embodiment, parameter setting of the analog unit is not required, and the function of the accuracy guarantee range can be implemented only by creating a program for the PLC acting as the master. Thus, there are advantages that the system can be easily constructed and started up.

[0100] 〔Embodiment 5〕 Other embodiments of the present invention will be described below.

[0101] FIG. 8 is a block diagram showing the configuration of the main part of the analog system 100e according to the fifth embodiment. In the fifth embodiment, unlike the first embodiment, a load cell input unit 4 is used instead of a temperature input unit as the analog unit. The load cell input unit 4 is an analog unit to which a load cell for detecting pressure is connected.

[0102] Unlike the analog system 100a, the analog system 100e is composed of a load cell input unit 4 instead of the temperature input unit 1a, a load cell 112 instead of the thermocouple 111, a control unit 10e instead of the control unit 10a, and a measured value acquisition unit 11e instead of the measured value acquisition unit 11. The measured value acquisition unit 11e has the same basic function as the measured value acquisition unit 11, but the difference is that it is a load cell input instead of a thermocouple input.

[0103] Figure 9 is a flowchart showing the procedure for specifying the accuracy guarantee range in the load cell input unit 4 according to Embodiment 5.

[0104] In S61, the accuracy guarantee specifying unit 13 checks whether the energization time of the load cell input unit 4 is equal to or longer than a predetermined time. If it is equal to or longer than the predetermined time (Yes in S61), the process proceeds to S62. If it is less than the predetermined time (No in S61), the process proceeds to S63.

[0105] In S62, the accuracy guarantee specifying unit 13 refers to the storage unit 20 and checks whether the input mode of the connected load cell 112 is a six-wire type. If it is not a six-wire type (No in S62), the process proceeds to S63. If it is a six-wire type (Yes in S62), the process proceeds to S64.

[0106] In S63, the accuracy guarantee specifying unit 13 determines that there is no guarantee for all accuracy items. The accuracy items in the load cell input unit include zero drift, gain drift, and non-linearity. The deviation widths due to ambient temperature changes in the intercept and slope in the linear approximation of the measured value and the actual pressure correspond to zero drift and gain drift, respectively, and non-linearity is an index representing the deviation between the linear approximation and the constitutive curve. The output unit 14 lights up the display of Rank0 on the display 141.

[0107] In S64, the accuracy guarantee specifying unit 13 checks whether the ambient temperature of the analog unit acquired by the environment information acquisition unit 12a is within a predetermined temperature range, whether the setting of the digital filter of the load cell input unit 4 is a predetermined value, and whether the full-scale setting is a predetermined value (predetermined range). If the conditions are not met (No in S64), the process proceeds to S65. If the conditions are met (Yes in S64), the process proceeds to S66.

[0108] In S65, the accuracy guarantee specifying unit 13 determines that there is a guarantee for some accuracy items. The accuracy items with a guarantee are zero drift and gain drift. Regarding non-linearity, the accuracy guarantee range is not determined. The output unit 14 lights up the display of Rank1 on the display 141.

[0109] In S66, the accuracy guarantee specifying unit 13 determines that there is a guarantee for all accuracy items. The output unit 14 lights up the display of Rank2 on the display 141.

[0110] In this way, even in the case of having a large number of accuracy guarantee ranges as an analog unit like the load cell input unit 4, all the accuracy guarantee ranges can be automatically specified. Also, the procedures for specifying the accuracy guarantee ranges may be different for each item, and there may be a case where the accuracy guarantee ranges can be specified for only some items.

[0111] 〔Embodiment 6〕 Other embodiments of the present invention will be described below. For the sake of convenience in explanation, members having the same functions as those described in the above embodiments are denoted by the same reference numerals, and the description thereof will not be repeated.

[0112] FIG. 10 is a block diagram showing the configuration of the main part of the analog system 100f according to Embodiment 6. In Embodiment 6, different from Embodiment 1, when using the analog output unit 5 instead of the temperature input unit as the analog unit, the method for obtaining the accuracy guarantee range is different. The analog output unit 5 is an analog unit that outputs an analog voltage or current corresponding to a digital value.

[0113] Unlike the analog system 100a, the analog system 100f is configured with an analog output unit 5 instead of the temperature input unit 1a and an analog device 113 instead of the thermocouple 111. The configuration of the analog output unit 5 is different from that of the temperature input unit 1a. It includes a control unit 10f instead of the control unit 10a and an analog value output unit 11f instead of the measurement value acquisition unit 11.

[0114] The analog value output unit 11f is equipped with a DA (Digital - Analog) converter inside. It converts the input digital value into an analog signal and outputs the analog signal to the analog device 113. The converted analog signal is either a voltage or a current. Also, the analog value output unit 11f may output the digital value to the accuracy guarantee specifying unit 13. In this case, the accuracy guarantee range may be calculated using the digital value.

[0115] FIG. 11 is a flowchart showing the procedure for specifying the accuracy guarantee range in the analog output unit according to Embodiment 6.

[0116] In S71, the environmental information acquisition unit 12a checks whether the ambient temperature is within a predetermined temperature range. If it is not within the predetermined temperature range (No in S71), the process proceeds to S72. If it is within the predetermined temperature range (Yes in S71), the process proceeds to S73.

[0117] In S72, the accuracy guarantee specifying unit 13 determines that the accuracy guarantee range is the first range. Also, the output unit 14 lights up the display 141 to display Rank1.

[0118] In S73, the accuracy guarantee specifying unit 13 determines that the accuracy guarantee range is the second range. The second range is a range that falls within the first range. That is, it can be said that the accuracy of the second range is higher than that of the first range. The output unit 14 lights up the display 141 to display Rank2.

[0119] As in the analog output unit 5, as an analog unit, not only in the case of analog input but also in the case of analog output, the accuracy guarantee range can be automatically specified.

[0120] [Embodiment 7] A use case of one aspect of the present invention will be introduced. This embodiment is an assumed case in a production apparatus that controls temperature by a furnace, when a temperature input unit is used for temperature control, based on Embodiment 1.

[0121] (Assumed case) From a certain period, defective products have frequently occurred in the production apparatus.

[0122] In order to investigate the cause of the defect, when the temperature inside the furnace was measured with another measuring instrument for temperature measurement, the temperature was different from the temperature indicated by the temperature input unit. The temperature error between the temperature input unit and the measuring instrument for temperature measurement was worse than the design accuracy of the apparatus.

[0123] Also, when the ambient temperature around the temperature input unit was measured with a measuring instrument for temperature measurement, it was found that the temperature had risen compared to when the production apparatus was delivered. Therefore, the accuracy guarantee range deteriorated, the furnace could not be controlled as intended, and the quality of the manufactured product deteriorated. When investigating the cause of the rise in the ambient temperature of the temperature input unit, it was found that the delivery time and season were different and the ambient temperature had risen.

[0124] If the present invention had not been implemented, even if it was found that the temperature inside the furnace could not be controlled as expected, it would take many trials such as device and unit replacement until reaching the true cause of the defect, which is the deterioration of the accuracy guarantee range of the temperature input unit, and a lot of man-hours would be required. During that time, defective products would continue to be produced, so the loss would also increase.

[0125] On the other hand, when implementing one aspect of the present invention, by checking the display 141, it can be immediately seen that the accuracy guarantee range is lower than the incorporation time. Therefore, it is possible to conduct a cause investigation from the perspective of why the accuracy guarantee range has decreased, and thus it is easy to reach the root cause. That is, troubles can be solved with low man-hours.

[0126] Also, when constantly monitoring the accuracy guarantee range by a program, at the stage of the change of seasons, a warning indicating that the accuracy guarantee range has deteriorated before defective products are produced can be issued, and it is easy to reach the root cause. Therefore, the occurrence of defective products can be suppressed, and troubles can be prevented in advance with low man-hours.

[0127] 〔Example of implementation by software〕 The control blocks of the temperature input units 1a·1b, PLCs 2c·2d, load cell input unit 4, or analog output unit 5 (particularly the measurement value acquisition units 11·11e, analog value output unit 11f, environmental information acquisition units 12a·12b, accuracy guarantee specification unit 13, and output unit 14) may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software.

[0128] In the latter case, the temperature input units 1a and 1b, the PLCs 2c and 2d, the load cell input unit 4, or the analog output unit 5 includes a computer that executes program instructions of software for realizing each function. This computer includes, for example, one or more processors and a computer-readable recording medium storing the above program. Then, in the above computer, when the above processor reads and executes the above program from the above recording medium, the object of the present invention is achieved. As the above processor, for example, a CPU (Central Processing Unit) can be used. As the above recording medium, in addition to a "non-transitory tangible medium" such as a ROM (Read Only Memory), a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, etc. can be used. Further, it may further include a RAM (Random Access Memory) for expanding the above program. Further, the above program may be supplied to the above computer via any transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. Note that one aspect of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the above program is embodied by electronic transmission.

[0129] 〔Supplementary Note〕 The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

Explanation of Reference Numerals

[0130] 1a, 1b, 3c, 3d Temperature input unit (information processing device) 2c, 2d PLC (information processing device) 4 Load cell input unit (information processing device) 5 Analog output unit (information processing device) 10a to 10f Control unit 11, 11e Measured value acquisition unit 11f Analog value output section 12a, 12b, 12d Environment information acquisition section (acquisition section) 13 Accuracy guarantee specifying section 14 Output section 15c, 15d Unit communication section 20 Memory section 100a~100f Analog system 111 Thermocouple 112 Load cell 113 Analog device 121 Temperature sensor 122 Acceleration sensor 141 Display (display device)

Claims

1. An accuracy guarantee specifying unit that specifies an accuracy guarantee range of an analog signal based on the analog signal handled by an analog unit and predetermined information regarding the analog signal, A storage unit that stores the predetermined information, and includes, The analog signal is a signal indicating a measured value of the analog device input from the analog device, The accuracy guarantee specifying unit calculates a range of values as the accuracy guarantee range using a reference accuracy and a temperature coefficient obtained using the current measured value, an information processing apparatus.

2. The information processing apparatus according to claim 1, wherein the predetermined information is information regarding a device that handles the analog signal.

3. The information processing apparatus according to any one of claims 1 to 2, wherein the predetermined information includes environmental information of the analog unit.

4. The information processing apparatus according to claim 3, further comprising an acquisition unit that acquires the environmental information.

5. The information processing apparatus according to claim 3 or 4, wherein the environmental information includes the ambient temperature of the analog unit.

6. The information processing apparatus according to any one of claims 3 to 5, wherein the environmental information includes the installation direction of the analog unit.

7. The information processing apparatus according to any one of claims 1 to 6, further comprising an output unit that outputs the accuracy guarantee range.

8. The information processing apparatus according to claim 7, wherein the output unit displays the level of the accuracy guarantee range on a display device.

9. The information processing apparatus according to any one of claims 1 to 8, wherein the analog signal is an input from a thermocouple.

10. The information processing apparatus according to any one of claims 1 to 8, wherein the analog signal is an input from a load cell.

11. An acquisition step of acquiring predetermined information regarding an analog signal handled by an analog unit from a storage unit, An accuracy guarantee specifying step of specifying an accuracy guarantee range of the analog signal based on the analog signal and the predetermined information, and including, The analog signal is a signal indicating a measured value of the analog device input from the analog device, In the accuracy guarantee specifying step, a range of values as the accuracy guarantee range is calculated using a reference accuracy and a temperature coefficient obtained using the current measured value, a control method of an information processing apparatus.

12. A program for an information processing apparatus for causing a computer to function as the information processing apparatus according to claim 1, the program for an information processing apparatus for causing a computer to function as the accuracy guarantee specifying unit.

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